Bulb



FIG. 1 is a perspective top View of a bulb;

FIG. 2 is a perspective bottom View thereof;

FIG. 3 is a front View thereof;

FIG. 4 is a rear View thereof;

FIG. 5 is a top View thereof;

FIG. 6 is a bottom View thereof;

FIG. 7 is a left side View thereof; and,

FIG. 8 is a right side View thereof.

CLAIM The ornamental design for a bulb, as shown and described.